The invention relates to a silver halide photographic light-sensitive material, and particularly to a color printing paper capable of obtaining printed images, and further detailedly to a color printing paper which is extremely less in fog and excellent in imaging characteristics.
In the prior art, a baryta paper was used, at the beginning, to serve as the support of a photographic printing paper. However, this kind of paper supports is not a little deficient. Namely, (1) paper will expand and contract; (2) a paper washing step will require a lot of time to remove a processing liquid because the processing liquid will permeate the paper; and (3) a ferrotyping treatment is required to dry up the paper, so that the installations and the energy burdens therefor may become expensive. With the purpose of improving the described deficiencies, the so-called polyolefin-laminated paper has been practically put in use, in which such a resin film as a polyethylene film is laminated on a paper support. This type of the supports comprises an intermediate paper mainly comprising a natural pulp, and a resin film layer for laminating the both surfaces of the intermediate paper. A variety of additives are added to the described natural pulps so as to improve the characteristics of such paper support. For example, Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 54436/1981 and the like each describe that there may be added with a dry paper strengthener, a sizing agent, a filter, a wet paper strengthener, a fixer, a pH adjuster, a dyestuff, an optical brightening agent and the like. With the purpose of improving the whiteness, titanium dioxide, a pigment and the like may be added to the lamination layer on the side to which an emulsion is to be coated.
It was found that the above described polyolefin-laminated paper was also not a little deficient. Namely, (1) the surface thereof is poor in smoothness; (2) the commercial value thereof is lowered because the pulp fibre stretches beard-like at the cut ends; (3) even if titanium dioxide is tried to add in an adequate amount to a polyolefin layer so as to improve the whiteness and the image sharpness of a printing paper, the amount of titanium dioxide to be added is limited to only 20% at a maximum; (4) the cut ends of a printing paper will be capable of hardening the surface of an intermediate paper when irradiating an electron beam thereto. Still in these methods, it was found a further deficiency that, when storing a printing paper prepared by coating an emulsion to the described support, there seriously affects such an emulsion characteristics as that the sensitivity of the printing paper is varied and a fog is increased and so on. The reason why the above-mentioned deficiency is caused is still not known yet, however, it may be presumed that the reason thereof may be that a compound having been contained in a printing paper is changed into a photographically active compound by the irradiation of an electron beam, and the resulting compound passes through a resin layer and immigrates into a photographic emulsion layer so that a fog core is formed.
With the purpose of compensating the above-mentioned deficiency, West German Patent (OLS) No. 3,046,130 Japanese Patent O.P.I. Publication No. 124336/1984 and the like describe respectively such a method that a polyolefin layer is used in combination with a hardened resin layer so as to serve as an interrupting layer. However, these methods can display only such an unsatisfactory effect that a time of causing a fog can only be delayed to some extent, and in addition, in these methods, the layer arrangement of the support will be increased, so that it is disadvantageous from the viewpoints of the costs and steps in manufacture.